Mitochondrial dynamics are controlled by a set of proteins, including Mfn1, Mfn2, Drp1 and hFis1, that regulate mitochondrial fission and fusion events. In addition, lack of MARCH5, a mitochondrial E3 ubiquitin ligase, has been shown to induce changes in mitochondrial morphology. On page 619, Hyeseong Cho and colleagues clarify the mechanisms by which MARCH5 regulates mitochondrial dynamics and cellular function. They show that RNAi-mediated knockdown of MARCH5 expression induces mitochondrial elongation, which, in turn, induces cellular senescence. In addition, they show that the ubiquitin-ligase activity of MARCH5 (attributed by its RING domain) is required for this effect, and that Mfn1 and Drp1 are two of its main substrates. The authors conclude that loss of MARCH5 expression disrupts the balance between mitochondrial fission and fusion through specific effects on Mfn1 and Drp1, which leads to the formation of a highly connected reticular network of mitochondria that imposes cellular stress and, in turn, senescence. These data define a role for MARCH5 in regulating mitochondrial-network dynamics in mammalian cells and relate changes in these networks to cellular senescence.

Pavan Vedula and Anna Kashina propose a new concept, the actin code, which encompasses the regulation of the essential functions of mammalian actins at the nucleotide level, rather than at the level of amino acids.

“To me, there are no real boundaries between chemistry, biology, physics and maths.”

Tony leads a group at the Mechanobiology Institute in Singapore, focusing on dissecting the structure–function relationship that underlies protein complexes that are involved in cell migration and adhesion. He shares his thoughts on why you don’t necessarily have to choose between the different branches of science that you find fascinating.

We also feature interviews with first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Check out our recent First Person interview with Julia Abitbol.

The second in our series of cell dynamics meetings now turns to organelles. This May 2019 meeting in Lisbon, Portugal, aims to bring together scientists studying the interface between organelles and the cytoskeleton at different scales and perspectives using a range of model systems. Find out more and register your interest here.

We are currently seeking proposals for four Workshops to be held in 2020. Do you have an idea for a Workshop? Please let us know and you could be one of our 2020 Workshop organisers. You focus on the science, we focus on the logistics. We are particularly keen to receive proposals from postdocs. Deadline date for applications is 25 May 2018.

Meet the preLighters! In the latest interview with our preLights community, the preLights team caught up with James Gagnon, Assistant Professor at the University of Utah, to talk about his research, how science can be made more open, his enthusiasm for the preLights project and the fun sides of being a junior PI.

Alexander García Ponce investigated how hematopoietic stem cell (HSC) cross the vascular wall and reach the bone marrow as part of his PhD project, with an aim to improving the outcome of HSC transplantation for individuals with leukaemia. A Travelling Fellowship from JCS allowed Alexander to advance his research at the Sanquin Blood Bank in The Netherlands. Read more on his story here.

Where could your research take you? Join Alexander and apply for the next round of Travelling Fellowships from JCS by 25 May 2018.